US4050064A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Four-level voltage supply for liquid crystal display
Assignee: Sharp Corp
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Filing: 1976-05-11
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Granted: 1977-09-20
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Expires: 1996-05-11
Abstract
Abstract A liquid crystal display enabling circuitry wherein the backplate electrode of a liquid crystal display is activated by a four-level voltage while the respective segment electrodes thereof are activated by a two-level voltage. This includes at least two input terminals, five output terminals, a voltage dividing resistor network and complementary MOSFET switching means and thereby provides the four-level voltage for the backplate electrode and the four-level voltage for the segment electrodes. In addition, this may be implemented with MOS integrated circuitry technology (and not bipolar integrated circuitry technology).
Inventors
- 👤 Shitaro Hashimoto
- 👤 Yuuichi Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 02:45
CPC Classifications
G; G09; G09G; G09G3/00; G09G3/04; G09G3/16; G09G3/18
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
132 words
Voltage supply circuitry for supplying to a liquid crystal display first, second and third voltage levels in addition to a reference level, comprising: first and second input terminals, the first input terminal being connected to the first voltage level and the second input terminal being connected to the reference level; first, second, third, fourth and fifth output terminals for providing desired voltage levels to the liquid crystal display; impedance means interposed between the first input terminal and the second input terminal for producing the second and third voltage levels; connection means for always providing the first and reference levels to the first output terminal and the fifth output terminal respectively; and switching means for selectively providing the first, second, third and reference voltage levels to the second, third and fourth output terminals.
Claim 2
Dependent Claim
132 words
Voltage supply circuitry for supplying to a liquid crystal display first, second and third voltage levels in addition to a reference level, comprising: first and second input terminals, the first input terminal being connected to the first voltage level and the second input terminal being connected to the reference level; first, second, third, fourth and fifth output terminals for providing desired voltage levels to the liquid crystal display; impedance means interposed between the first input terminal and the second input terminal for producing the second and third voltage levels; connection means for always providing the first and reference levels to the first output terminal and the fifth output terminal respectively; and switching means for selectively providing the first, second, third and reference voltage levels to the second, third and fourth output terminals.
Claim 3
Dependent Claim
47 words
A voltage supply circuitry as defined in claim 1 wherein the first voltage level is selected equal to the threshold level of voltage which initiates a change in the optical characteristics of the liquid crystal display and the reference voltage level is selected equal to ground potential.
Claim 4
Dependent Claim
33 words
A voltage supply circuitry as defined in claim 2 wherein the impedance means includes four resistors for dividing the potential difference between the first voltage level and the reference voltage level by three.
Claim 5
Dependent Claim
16 words
A voltage supply circuitry as defined in claim 1 wherein the switching means includes complementary transistors.
Claim 6
Dependent Claim
18 words
A voltage supply circuitry as defined in claim 4 wherein the complementary transistors are implemented with CMOS technology.
Claim 7
Dependent Claim
19 words
A voltage supply circuitry is defined in claim 1 wherein the liquid crystal display is of the multi-digit type.
Claim 8
Dependent Claim
27 words
A voltage supply circuitry as defined in claim 6 wherein each digit of the liquid crystal display comprises a common electrode and a plurality of segment electrodes.
Claim 9
Dependent Claim
29 words
A voltage supply circuitry as defined in claim 6 wherein the common electrode is activated by a four-level voltage while the segment electrodes are activated by a four-level voltage.
Claim 10
Dependent Claim
49 words
A voltage supply circuitry as defined in claim 8 wherein the four-level voltage alternates between the first voltage level and the reference level when the liquid crystal display is to be activated, and alternates between the second and third voltage levels when the same is not to be activated.
Claim 11
Dependent Claim
26 words
A voltage supply circuitry as defined in claim 8 wherein the segment activating means includes complementary MOSFET's responsive to information signals derived from an information storage.
Claim 12
Dependent Claim
30 words
A voltage supply circuitry as defined in claim 8 wherein the common electrode activating means includes a series connection of complementary MOSFET's responsive to timing signals derived from a counter.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-09-19 | 1981-03-21 | 1981-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-19 | 1985-03-21 | 1985-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-19 | 1989-03-21 | 1989-09-20 | $7700.00 | Window Closed / Lapsed |